Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

For the first time, researchers have developed a way to accurately measure how heat flows within carbon nanotubes–tiny molecular wires that could someday be used to make circuits that are much faster and more energy efficient than today’s. The results show that nanotube heating is more complicated than previously thought–a fact that could be crucial in enabling engineers to build carbon-nanotube electronics.

Traditional semiconductors, such as silicon, undergo heating, says Phaedon Avouris, leader of IBM’s nanoscale science and technology group in New York, where the work was carried out. “It’s one of the limitations in improving speed,” says Avouris. But the study published by his team today in Nature Nanotechnology “goes beyond the simple observation of heat” in carbon nanotubes, he says. “It goes to the atomic level of how heat is generated and dissipated.”

In particular, Avouris’s team found that when an electrical current is applied to a nanotube transistor, some atomic vibrations can produce heat of up to 1,000 °C, while other vibrations produce a relatively cool temperature of 400 °C. This is contrary to the behavior of most materials, which maintain a relatively uniform heat.

Moreover, the researchers found that the electrical properties of a nanotube, and the manner in which heat is transferred to a substrate made from the silicon dioxide, are both affected by the vibrations of atoms on the surface of the substrate. This means that the substrate used with nanotube transistors will play an important role in determining the electrical properties of the transistor, and the manner in which heat can be removed.

Since about 1998, when the first carbon-nanotube transistor was demonstrated, researchers have dreamed of next-generation electronics made from such components. Nanotubes have novel properties that allow electrons to zip through them quickly, at low power, and researchers believe that they could act as the active component in transistors, outpacing those made of silicon in terms of speed, energy efficiency, and compactness. But understanding how nanotubes heat up when an electric current is passed through them has been a roadblock to building reliable nanotube circuits.

Mathais Steiner, a researcher at IBM’s nanoscale science and technology group, who also worked on the project, says that in the past couple of years, scientists have turned their attention to the way that nanotubes heat, but this property has been difficult to measure. “The problem is that it’s difficult to probe properties of the active channel [the region of nanotube used as the electrical switch in a transistor] because we’re talking about one molecule,” he says. “People were wondering how to get data and perform experiments. This is the first one to get results.”

0 comments about this story. Start the discussion »

Credit: IBM

Tagged: Computing, Materials, carbon nanotubes, transistors, circuits, heat

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me